JP6758131B2 - Composite non-woven fabric and its manufacturing method - Google Patents

Description

The present invention relates to a composite non-woven fabric composed of pulp fibers and synthetic fibers and a method for producing the same. More specifically, it relates to a non-woven fabric suitable for a so-called wiper used as a towel, a washcloth, a towel, a waste cloth and the like.

The non-woven fabric has a cloth-like texture, has liquid absorption and wiping properties (sometimes referred to as scraping properties), and can be mass-produced. Therefore, non-woven fabrics are widely used in various fields.
Generally, a non-woven fabric is produced through a web forming step of forming a web (sometimes called a fleece) as a base material and a fiber bonding step of binding the fibers constituting the web to each other. Many proposals have been made conventionally for each of the web forming step and the fiber bonding step.

For example, as disclosed in Patent Document 1, a pulp fiber layer (web) and a synthetic fiber layer (web) are overlapped to form a laminated web, and then a high-pressure water jet (water flow) is sprayed to perform a water flow confounding treatment. The fibers can be combined to obtain a composite non-woven fabric. As described above, the composite non-woven fabric formed by the pulp fiber layer and the synthetic fiber layer has advantages of the pulp fiber having good absorption to both water-based and oil-based liquids and the synthetic fiber having excellent strength. An excellent non-woven fabric product that also has the above can be provided to consumers as a wiper.

Japanese Patent No. 2533260

It is desirable that the non-woven fabric used as a wiper has improved liquid absorption performance and wiping performance as compared with a normal non-woven fabric.
Here, for example, a non-woven fabric having a larger basis weight can be expected to have higher liquid absorption. However, when the basis weight becomes large, the so-called stiff feeling increases and the adhesion to the object to be wiped is impaired. Therefore, a non-woven fabric that can satisfy both liquid absorption and wiping properties is desired, but a non-woven fabric suitable for a wiper that satisfies this requirement has not yet been provided.
It is also conceivable to apply a surface treatment to the manufactured non-woven fabric web (before or after drying) in order to improve the liquid absorption property and the wiping property. However, in this case, an additional device for that purpose is required, which causes an increase in cost due to an increase in manufacturing equipment. Therefore, it is preferable that the non-woven fabric to be manufactured itself is in the state of the original fabric and has excellent liquid absorption and wiping properties, but the non-woven fabric suitable for the wiper designed from such a viewpoint is preferable. Has not previously existed.

Therefore, a main object of the present invention is to provide a non-woven fabric suitable for a wiper, which is a composite non-woven fabric in which a pulp fiber layer is laminated and integrated on a synthetic fiber layer. Another object of the present invention is to provide a manufacturing method capable of manufacturing this non-woven fabric relatively easily.

The above object is a method for producing a composite type non-woven fabric in which a pulp fiber layer is laminated on a synthetic fiber layer and integrated, and is placed on the synthetic fiber layer and the synthetic fiber layer. A water flow entanglement step of spraying a water jet toward the preliminary laminate formed by the pulp fibers to perform a water flow entanglement treatment and promoting the integration of the pulp fiber layer and the synthetic fiber layer is included at least, and the above. In the water flow entanglement step, the preliminary laminate is placed on a transport wire and transported, and the water jet is sprayed toward the pulp fiber layer from a plurality of water flow injection nozzles arranged in a direction perpendicular to the transport direction, and the above. A plurality of streaky uneven portions are formed on the surface of the pulp fiber layer by sucking with a suction device arranged under the transport wire and using a position corresponding to the water flow injection nozzle as a recess. The water flow injection nozzle has a nozzle diameter of 0.15 to 0.25 mm, and the plurality of water flow injection nozzles are arranged in a plurality of stages along the transport direction, and the second water flow by the plurality of stages of the water flow injection nozzle is provided. Before and after the entanglement treatment, a first water flow entanglement treatment is performed in which a water jet is sprayed onto the entire surface of the pulp fiber layer using a water flow injection nozzle having a diameter smaller than that of the multi-stage water flow injection nozzle. Achieved by the method of manufacturing the non-woven fabric.

Further, the above object is a method for producing a composite type non-woven fabric in which a pulp fiber layer is laminated on a synthetic fiber layer and integrated, and is placed on the synthetic fiber layer and the synthetic fiber layer. Water flow entanglement treatment is performed by spraying a water jet toward the preliminary laminate formed by the pulp fibers to be formed, and at least includes a water flow entanglement step for promoting integration of the pulp fiber layer and the synthetic fiber layer. In the water flow entanglement step, the preliminary laminate is placed on a transport wire and transported, and the water jet is sprayed toward the pulp fiber layer from a plurality of water flow injection nozzles arranged in a direction perpendicular to the transport direction. At the same time, suction is performed by a suction device arranged under the transport wire, and the transport wire is formed by a plurality of warp threads and weft threads, and at least one of the warp threads and the weft threads has a diameter thicker than that of the other threads. It has a form in which a plurality of thick threads are arranged at intervals, and by forming a plurality of recesses on the surface of the pulp fiber layer corresponding to the positions of the thick threads, a plurality of streaky uneven portions or a plurality of streaky uneven portions or a plurality of. It is also achieved by a method for producing a composite type non-woven fabric that forms uneven portions in a vertical and horizontal lattice pattern.

In addition, you may adopt the manufacturing method which manufactures the composite type nonwoven fabric by combining the two manufacturing methods described above.

Since the non-woven fabric of the present invention has a plurality of uneven portions formed on the pulp fiber layer on the synthetic fiber layer, it is excellent in liquid absorption and wiping property, and is a non-woven fabric suitable as a wiper.
The non-woven fabric having the morphological property that the pulp fiber layer is provided with a plurality of uneven portions in the state of the original fabric is manufactured by the manufacturing method proposed in the present invention with a simple improvement in the manufacturing process. can do.
It should be noted that any unevenness can be formed on the non-woven fabric obtained in the conventional general manufacturing process by using, for example, an embossing apparatus provided with heating and pressurizing means. However, in this case, an embossing device is further required, and there is a concern that the texture and strength of the non-woven fabric may be lowered by the heat treatment. The non-woven fabric of the present invention is a non-woven fabric in which such concerns have been dispelled.

It is a figure which showed typically the composite type nonwoven fabric which concerns on this invention. It is a figure which showed the basic structure of the manufacturing apparatus for manufacturing the composite type nonwoven fabric which concerns on this invention. It is a figure shown for demonstrating the 1st method for manufacturing a composite nonwoven fabric. It is a figure shown for demonstrating the 2nd method for manufacturing a composite nonwoven fabric. It is a figure shown for demonstrating the 3rd method for manufacturing a composite nonwoven fabric.

Hereinafter, the composite nonwoven fabric according to the embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing a part of a composite non-woven fabric CWeb. In FIG. 1, a synthetic fiber layer made of a synthetic fiber web SW located on the lower side (hereinafter, may be referred to as a synthetic fiber layer SW) and a pulp fiber layer made of a pulp fiber FP arranged on the synthetic fiber layer (hereinafter, may be referred to as a synthetic fiber layer SW). , Pulp fiber layer FP) is shown schematically for easy understanding.
The non-woven fabric CWeb according to the present invention is a composite non-woven fabric in which the synthetic fiber layer SW and the pulp fiber layer FP are integrated. Then, FIG. 1 illustrates a form in which a plurality of uneven portions are repeatedly formed in the same form on the surface of the pulp fiber layer FP located on the upper side.

The uneven portion is composed of the concave portion DE and the convex portion PR, but if the concave portion (or the convex portion) is repeatedly formed on the surface of the pulp fiber layer FP at intervals, the convex portion (or the concave portion) is relatively formed between them. Will be.
FIG. 1 illustrates a non-woven fabric CWeb in which a plurality of uneven portions DE and PR are formed in a streak pattern. The method for producing the non-woven fabric CWeb will be clarified in the description below.
Further, although not shown, a plurality of the uneven portions DE and PR may be formed in a vertical and horizontal lattice shape (mesh shape or mesh shape). The method for producing the non-woven fabric CWeb will also be clarified in the description below.

In the above-mentioned non-woven fabric CWeb according to the present invention, pulp fibers are arranged on the surface thereof, and the surface has uneven portions, so that the surface area is increased and the liquid absorption performance is improved. In addition, since it also has a function of retaining dirt scooped up by the convex portion in the concave portion, the wiping performance is also improved.
Therefore, the non-woven fabric is suitable for wipers with improved liquid absorption and wiping properties. This non-woven fabric CWeb is obtained by a novel manufacturing method, and has a plurality of uneven portions on the surface pulp fiber layer as a morphological characteristic of the web raw fabric. Therefore, the non-woven fabric is excellent in flexibility, texture, and bulkiness.
From the viewpoint of ensuring the liquid absorption performance and the wiping performance of the non-woven fabric CWeb, the height difference between the bottom of the concave portion DE and the top of the convex portion PR of the uneven portions DE and PR is, for example, 200 to 800 μm. It is preferable to do so. As a result, reliable wiping performance can be expected.
Further, the width of the convex portion PR is preferably 0.5 to 3.0 mm, and the predetermined interval (width of the concave portion DE) is preferably 0.3 to 1.0 mm, for example.

Hereinafter, a method for producing the above-mentioned non-woven fabric CWeb will be described. There are three suitable forms of the manufacturing method. First, the main configuration of the non-woven fabric CWeb manufacturing apparatus will be described, and then the characteristic configurations of each manufacturing method will be individually described.
The composite non-woven fabric manufacturing apparatus 1 shown in FIG. 2 has an air raid apparatus 2 as a pulp air raid portion, a synthetic fiber web supply apparatus 3 as a synthetic fiber layer supply portion, and a suction device 4 as a laminate forming portion on the upstream side. It is installed. The suction device 4 is arranged so as to face the lower side of the air raid device 2.
In the transport direction TD, a water flow injection (water jet) device 5 as a water flow confounding part and a drying device 6 as a dehydration / drying part are arranged in order from the upstream side downstream of these devices 2, 3 and 4. .. Downstream of the drying device 6, a winding device 7 for winding a continuously manufactured composite non-woven fabric CWeb is further provided.

The air raid device 2 is provided with a defibrator 21 for defibrating (also referred to as opening) the raw pulp RP, which is a sheet of raw pulp RP in which fibers are densely packed, into pulp fibers, and a blower (not shown). It has a duct 22 and the like for transporting the pulp fiber FP to the air raid hopper 23. The air raid hopper 23 is designed so that the defibrated pulp fiber FP descends while being dispersed inside the air raid hopper 23 and gradually stacks at the stacking position 24 set on the lower surface.
A suction device 4 is arranged opposite to the lower side of the stacking position 24. More specifically, the suction device 4 has a suction portion 42 on the upper surface of the apparatus main body 41, and the suction portion 42 is set with respect to the stacking position 24 so as to apply a suction force (negative pressure) to the pulp fiber FP. It is done.

Further, a transport wire 43 for web transport is arranged around the suction device 4. The transfer wire 43 is arranged so that the pulp fiber FP can be placed at the stacking position 24 and is conveyed to the downstream side. However, the pulp fiber FP is not directly placed on the transport wire 43. This will become clear in the description below.
The transport wire 43 is formed in an opening form (mesh) so that the suction force of the suction portion 42 extends to the opposite side (upper side).

Conventionally known pulp can be used as the raw material pulp RP. For example, when wood pulp is used, NBKP such as radiata pine, slash pine, southern pine, spruce, and Douglas fir is preferable as the grade, and it may be appropriately selected in consideration of defibration, yield and the like.
Further, since the raw material pulp RP is often supplied in the form of roll pulp as illustrated, it is preferable to adopt a hammer mill, a disc mill type or the like as the defibrating device 21. The defibration treatment here may be performed in one stage or a plurality of stages, if necessary.
Further, natural fibers such as cotton and synthetic fibers such as polyester, polypropylene and polyethylene may be additionally blended together with the raw material pulp RP. When adopting such a composition, a separate air raid head may be added to superimpose the web layer, or an air blowing line for mixing another fiber may be added to the duct for airing the opened pulp.

The synthetic fiber web supply device 3 is arranged below the air raid device 2 and upstream of the suction device 4. A synthetic fiber web SW prepared in advance is set in the synthetic fiber web supply device 3 in a roll shape. The synthetic fiber web SW is pulled out from the synthetic fiber web supply device 3 and is conveyed to the laminated position 24 on the conveying wire 43 described above.
As the synthetic fiber web SW, it is preferable to use a web of continuous filaments formed by the spunbond method. The synthetic fiber here is preferably selected from nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, polystyrene and the like.

The pulp fiber FP described above is placed (stacked) on the synthetic fiber web SW located at the stacking position 24, and the synthetic fiber web SW is transported downstream on the transport wire 43.
At that time, at the laminated position 24, the suction force by the suction portion 42 of the suction device 4 passes through the transport wire 43 and acts on the synthetic fiber web SW and the pulp fiber FP on the transfer wire 43. Therefore, in the laminated web that has moved to the downstream side through the lamination position 24, the lower synthetic fiber layer (synthetic fiber web SW) and the pulp fiber layer (pulp web) placed on the lower synthetic fiber layer are laminated. It becomes a preliminary laminated body PWeb in the state of being in a state of being.

The preliminary laminated body PWeb described above is maintained in a laminated state by being suction-compressed by the suction force of the suction device 4. At this time, the pulp fiber layer on the upper side is in a state where the pulp fiber FP is densely packed. However, if the preliminary laminated body PWeb is conveyed and thrown into the water flow injection device 5 on the downstream side as it is, a part of the pulp fiber FP may fly up due to the water flow (water jet).
Therefore, in the present manufacturing apparatus 1, the holding roller 28 for stabilizing the placement state of the pulp fiber FP on the synthetic fiber web SW by sandwiching the preliminary laminated body PWeb from above and below, and the upstream side of the water flow injection device 5. A pre-wet device 30 for imparting water to the pulp fiber FP to prevent scattering is provided. The pre-wet device 30 preferably applies a suction force from the spray nozzle 31 that sprays water mist from above the preliminary laminate PWeb and the lower side of the preliminary laminate PWeb (that is, the lower surface of the synthetic fiber web SW). It is configured to include a suction device 32.

The sandwiching roller 28 and the pre-wet device 30 can be understood as a pretreatment unit for smooth execution of the water flow entanglement processing in the water flow injection device 5. The pretreatment section shown in FIG. 2 is a suitable configuration example, and the sandwiching roller 28 may be omitted.

The water flow injection device 5 promotes entanglement of pulp fibers by spraying a high-pressure water jet on the preliminary laminated body PWeb treated by the pretreatment units 28 and 30. This promotes the integration of the pulp fiber layer located on the upper side and the synthetic fiber layer located on the lower side.
In the water flow injection device 5 exemplified in FIG. 2, water flow injection nozzles 51 are arranged in multiple stages (four stages are illustrated in FIG. 2) along the transport direction TD. By spraying the water flow injection nozzle of the first stage at a low pressure, the pre-wet device 30 described above may be substituted.
In FIG. 2, the state of the nozzles in the direction perpendicular to the transport direction TD (the width direction of the device 1) is not shown, but a plurality of water flow injection nozzles are also arranged in the width direction.

It is desirable that the water pressure at the time of performing the water flow confounding treatment is set in consideration of the basis weight of the pulp fiber layer (web) and the synthetic fiber layer (web). For example, it is preferable to select in the range of 1 to 30 MPa.

The suction device 52 is arranged so as to face the water flow injection nozzle 51. While spraying the high-pressure water jet emitted from the water flow injection nozzle 51 onto the pulp web located on the upper side, the suction force of the suction device 52 is applied to the lower side of the synthetic fiber layer located on the lower side. By the cooperative action of the water flow injection nozzle 51 and the suction device 52, the pulp fibers of the pulp web have entered the fibers of the synthetic fiber web on the lower side, or have penetrated the synthetic fiber web to reach the opposite side. Is presumed to be formed. The action promotes the integration of the two layers.

The transport wire 55 is also arranged in the water flow injection device 5. The transfer wire 55 receives the preliminary laminated body PWeb downstream of the pretreatment units 28 and 30, and transfers the transfer wire 55 into the water flow injection device 5. The transfer wire 55 is arranged so as to pass between the water flow injection nozzle 51 of the water flow injection device 5 and the suction device 52 from the upstream side to the downstream side.
Therefore, the preliminary laminated body PWeb transported on the transport wire 55 is subjected to more water flow entanglement treatment as it goes downstream in the transport direction TD, and when it exits the water flow injection device 5, the upper pulp fiber Sufficient entanglement between the layer and the lower synthetic web is achieved.
Immediately after leaving the water flow injection device 5, the web is in a wet state, and the bond between the pulp fibers is not sufficiently established before drying.

Therefore, a drying device 6 for removing water from the wet web is provided on the downstream side of the water flow injection device 5. The drying device 6 illustrated here is preferably an air-through dryer. The rotatable dryer body 61 is a tubular body, and a large number of through holes are provided on the peripheral surface thereof, and hot air heated by a heat source (not shown) radiates from the central side of the dryer body 61 toward the outer periphery. It is a structure that blows out. Therefore, when the wet web comes out of the drying device 6, it is sufficiently dried and the fibers are completely bonded to each other, resulting in a finished composite non-woven fabric CWeb. The composite non-woven fabric CWeb continuously produced in this way is wound by the roller 71 of the winding device 7 to complete a series of steps.

The basic configuration of the manufacturing apparatus for manufacturing the composite nonwoven fabric according to the present invention has been described above. Hereinafter, a specific configuration for forming the uneven portion on the pulp fiber layer will be described.
As described above, the manufacturing apparatus 1 for manufacturing the nonwoven fabric CWeb includes a water flow injection device 5 that performs a water flow entanglement treatment, and includes a water flow injection nozzle 51 and a suction device 52 arranged so as to face the water flow injection nozzle 51. The entanglement process is realized by feeding and transporting the preliminary laminated body PWeb in the meantime.
The manufacturing method of the present invention is characterized by a wet web (original fabric) emitted from the water flow injection device 5, and a non-woven fabric CWeb in which uneven portions are formed on the pulp fiber layer on the surface is manufactured with a simple configuration. It is an invention that makes it possible. Hereinafter, the three inventions will be described in order.

FIG. 3 is a schematic view shown for explaining a first method for producing a composite nonwoven fabric in which uneven portions DE and PR are formed on the pulp fiber layer FP. FIG. 3 shows an enlarged view of a partial configuration of the water flow injection device 5 and a peripheral portion related thereto. Specifically, the plurality of water flow injection nozzles 510 arranged in a direction perpendicular to the transfer direction TD, the transfer wire 55, and the suction device 52 and the transfer wire 55 arranged below the transfer wire 55 are mounted on the transfer wire 55. FIG. 3 schematically shows the state of the preliminary laminated body PWeb.
In the configuration shown in FIG. 3, the water flow injection nozzle 510 has a nozzle diameter set to, for example, 0.15 to 0.25 mm. A general conventional water flow injection nozzle has a smaller diameter than the water flow injection nozzle 510, for example, a nozzle diameter of 0.05 to 0.15 mm. Since the amount of jet water is proportional to the square of the nozzle diameter, the water flow jet nozzle 510 can discharge more water than before.
As will be described later, when water flow confounding is performed by using a water flow injection nozzle 510 having a larger diameter (larger diameter) than the conventional one and a conventional water flow injection nozzle, the water flow injection nozzle 510 is used with the conventional water flow injection nozzle. It is preferable to set the diameter to 1.2 to 2.0 times the diameter. This is because it is preferable to adopt a conventional water flow injection nozzle having a small diameter of 0.5 to 0.83 times the diameter when viewed with reference to the diameter of the water flow injection nozzle 510.
The water pressure of the water flow injection nozzle is preferably 1 to 30 MPa as described above, and when the water flow injection nozzle 510 having a relatively large diameter is adopted, the arrangement pitch is widened as compared with the conventional case, and the per width is per. The number of arrangements may be reduced and set.

Generally, since the suction device 52 is arranged under the synthetic fiber SW, the water flow from the water flow injection nozzle is penetrated through the preliminary laminated body PWeb while removing excess water to match the water flow. The fibers can be entangled with each other. At that time, in the present invention, since the water flow injection nozzle 510 uses a nozzle having a larger diameter (thicker) than the conventional one, the pulp fiber layer FP in the center of the water flow is repelled (repelled) or eliminated. Occurs. More specifically, the suction device 52 is arranged under the water flow injection nozzle 510, but in the case of a water flow thicker than the conventional one, the suction force from below cannot partially cope with it. As a result, the pulp fiber layer FP having a relatively low rigidity on the upper side of the preliminary laminated body PWeb is formed with a concave shape at the corresponding position of the water flow injection nozzle 510. Since the preliminary laminated body PWeb is conveyed on the transfer wire 55 in the transfer direction TD, a plurality of streaky uneven portions (concave DE, convex portion PR) are formed toward the downstream as shown in FIG. Will be done.

The water flow injection nozzle 510 according to FIG. 3 is larger than the conventional water flow injection nozzle, is reduced in number as compared with the conventional water flow injection nozzle, and is arranged at a wide interval. This interval corresponds to the interval of the concave portion DE, and the convex portion PR is formed between them. Note that FIG. 3 schematically shows the state of the pulp fiber layer FP so that the invention can be easily understood.

As shown in FIG. 2, the water flow injection nozzle 51 and the suction device 52 in the water flow injection device 5 are formed in multiple stages (the example in FIG. 2 is four stages) along the transport direction TD.
Also in the case of carrying out the invention according to FIG. 3, the water flow injection nozzles 510 are arranged in multiple stages as shown in FIG. 2, and the water jet by the water flow injection nozzles 510 is repeatedly sprayed toward the same position of the preliminary laminated body PWeb. The recess DE can be reliably formed. It goes without saying that the number of stages of the water flow injection nozzle 510 may be arbitrarily set as necessary in order to more reliably form the recess DE. In this case, it is preferable that the equipment allows fine adjustment of the nozzle position.

By the way, when the water flow injection nozzle has four stages as in the embodiment shown in FIG. 2, it is preferable to perform the treatment as follows.
As for the first-stage water flow injection nozzle 51, a conventional type (smaller diameter than the water flow injection nozzle 510 in FIG. 3) is used, and water flow confounding is used to blow a water jet toward the entire surface of the pulp fiber layer FP. The treatment (first water flow entanglement) is performed to entangle the entire pulp fibers.
Next, with respect to the second and third stages of the water flow injection nozzle 51, uneven portions are formed by using the water flow injection nozzle 510 having a large diameter with the nozzle diameter described in FIG. 3 being 0.15 to 0.25 mm. The water flow entanglement treatment (second water flow entanglement treatment) is executed.
Then, with respect to the final fourth-stage water flow injection nozzle 51, as in the first first stage, a conventional small-diameter water flow injection nozzle is used to apply a water jet toward the entire surface of the pulp fiber layer FP. It is more preferable to carry out the spraying water flow entanglement treatment.

When the first water flow entanglement treatment, which is the conventional water flow entanglement treatment, is performed at the beginning and the end as described above, it is possible to prevent the initial unfixed fibers from scattering, so that a clearer pattern can be formed. Can be done. Then, since the pulp fiber layer FP and the synthetic fiber SW can be entangled as a whole at the end, a stronger composite non-woven fabric CWeb can be obtained.
If the second water flow entanglement treatment (water flow entanglement treatment having a large nozzle diameter) is performed first, unentangled pulp fibers may be scattered by the large diameter nozzle, which deteriorates the appearance and causes an uneven pattern. There is concern that it will be disturbed. It is also not preferable to finish the second water flow entanglement treatment. This is because the entanglement of the pulp fibers that have moved to the convex portion remains in an insufficient state, and the entanglement of the entire web is not completed.

FIG. 4 is a diagram shown for explaining the second method. FIG. 4 also shows an enlarged view of a partial configuration of the water flow injection device 5 and a peripheral portion related thereto. A plurality of water flow injection nozzles 51 arranged in a direction perpendicular to the transfer direction TD, a transfer wire 55, and a suction device 52 arranged below the transfer wire 55, and the preliminary laminated body PWeb mounted on the transfer wire 55. FIG. 4 is the same as FIG. 3 in that the state of is schematically shown.

Here, the points different from the first method will be mainly described. In the suction device 52 shown in FIG. 4, a water-impermeable portion 521 is provided in an opening 520 provided for applying a suction force. The impermeable portion 521 functions as a baffle plate arranged so that the suction force does not act. A plurality of impermeable portions 521 are arranged at intervals in a direction perpendicular to the transport direction TD. A suction force does not act on the preliminary laminated body PWeb in the portion where the impermeable portion 521 exists. On the other hand, a suction force acts on a portion where the impermeable portion 521 does not exist. As a result, a state in which the pulp fibers escape (wrap around) is formed on both sides of the impermeable portion 521 on which the suction force acts. As a result, the pulp fiber layer at the position corresponding to the impermeable portion 521 becomes the concave portion DE, and the pulp fiber layer at the position where the suction force acts between the impermeable portions 521 becomes the convex portion PR.
The impermeable portion 521 preferable for forming the concave portion DE has a width of, for example, 1 mm or more, and is preferably set at an interval of 3 to 5 mm.
The suction force (negative pressure) of the suction device 52 is preferably 0.01 to 0.05 (Mpa), for example. Here, 0.01 MPa is equal to 100 mbar or 75 mmHg.

In the case of FIG. 4, as in the case of FIG. 3, the suction devices 52 in which the impermeable portions 521 are formed at the same positions are arranged in multiple stages in the transport direction TD to ensure that the uneven portions are formed. Is preferable.
The suction devices 52 located at the beginning and the end are not provided with the impermeable portion 521, and the suction force is applied to the entire preliminary laminated body PWeb to entangle the pulp fiber layer FP and the synthetic fiber SW as a whole. It is preferable to realize this. This point has the same meaning as the water jet is finally sprayed on the entire surface of the pulp fiber layer FP in the first manufacturing method shown in FIG.
The water flow injection nozzle 51 illustrated in FIG. 4 is a conventional type, has a nozzle diameter of 0.05 to 0.15 mm, and may spray a water jet on the entire surface of the pulp fiber layer FP.
As described above, the composite non-woven fabric in which the uneven portion is formed on the surface of the pulp fiber layer can also be manufactured by the manufacturing method using the suction device 52 shown in FIG.

Further, a third manufacturing method will be described. Conventionally, in a transport wire, a plurality of warp threads and weft threads are generally arranged in a mesh shape and composed of threads having the same thickness. In the third manufacturing method, a composite non-woven fabric is manufactured by performing a water flow entanglement treatment using a new transport wire different from the transport wire of the general concept.
FIG. 5 shows an enlarged view of a part of the transfer wire 550, which is an example that can be adopted in the third manufacturing method. Among the plurality of warp threads 551, the transfer wire 550 has warp threads 551B having a diameter larger than that of the other warp threads for each predetermined number (every 5 threads in the example). The warp 551 is parallel to the transport direction TD.

Similarly, in the transport wire 550, weft threads 552B having a diameter larger than that of the other weft threads are arranged for each predetermined number (every 5 threads in the example) among the plurality of weft threads 552.
Here, the warp 551 and the weft 552 of the transport wire 550 have a general diameter of 0.2 to 0.6 mm, but the thick warp 551B and the thick warp 551B preferably have a diameter of, for example, 1 mm or more. Alternatively, it is preferable to set the diameter of the thick thread to, for example, 3 to 5 times the diameter of the other threads. As a result, uneven portions can be reliably formed on the surface of the pulp fiber layer. In this case, the aperture ratio of each of the warp and weft is preferably 10% or more, and more preferably 20 to 30%. The aperture ratio (%) here is defined based on the number of threads existing within 1 cm and the diameter of the threads. Specifically, the aperture ratio (%) can be calculated by the formula [(1-number of threads × thread diameter) / 1] × 100 (%).

When the water flow entanglement treatment is performed by the water flow injection device 5 using the transfer wire 550 as described above, recesses are formed in the pulp fiber layer at the position corresponding to the position (region) where the thick yarn exists. Since the action of the suction force on the pulp fiber layer existing on the thick thread is limited, a state in which the pulp fiber escapes (wraps around) is formed on both sides on which the suction force is acting. As a result, convex portions are formed in the pulp fiber layer on both sides of the thick yarn, and concave portions are formed corresponding to the positions where the thick yarn is present.
As described above, by devising the transport wire used for the water flow injection device 5, it is possible to manufacture a composite non-woven fabric in which uneven portions are formed in the pulp fiber layer.

The transport wire 550 shown in FIG. 5 illustrates a case where thick threads are arranged in both the vertical and horizontal directions, and when the transport wire 550 is used, the uneven portions having a vertical and horizontal lattice pattern are pulp. It is formed on the surface of the fiber layer.
When a thick yarn is arranged only on the warp side of the transport wire 550, a streak-like uneven portion along the transport direction TD can be formed on the surface of the pulp fiber layer in the same manner as in the first and second manufacturing methods described above. ..
Contrary to the above, when a thick thread is arranged only on the weft side with the transfer wire 550, it is along a direction perpendicular to the transfer direction TD, which cannot be produced by the above-mentioned first and second manufacturing methods. Streaky irregularities (parallel to the direction) can also be formed on the surface of the pulp fiber layer.
The arrangement of the threads in FIG. 5 is merely an example. When the transport wire 550 is manufactured by a knitting machine, if the weft threads are changed for each predetermined number, the manufacturing process becomes extremely complicated. Therefore, all the weft threads may be the thick threads described above. In this case, since the thick threads are arranged at predetermined intervals, convex portions are formed on the surface of the pulp fiber layer corresponding to the positions corresponding to the thick threads.

According to the first to third manufacturing methods described above, a composite non-woven fabric in which uneven portions are formed on the surface of the pulp fiber layer can be manufactured by simply making simple changes to the basic non-woven fabric manufacturing apparatus.
In the description of the first to third manufacturing methods, the case where the uneven portions are repeated in the same pattern is illustrated, but this is merely an example. Depending on the product requirements of the non-woven fabric, there are cases where the concave and convex parts have the same width or different widths from each other, or when it is desired to manufacture a non-woven fabric whose design is that the concave and convex parts are irregularly changed. is there. In such a case, the positions and arrangement settings of the thick threads (551B and 552B) in the water flow injection nozzle (510), the impermeable portion (521) and the transfer wire (550) described above should be appropriately changed. Just do it.
Further, in the above, the first, second, and third manufacturing methods have been described individually, but if necessary, these may be appropriately combined to manufacture a composite non-woven fabric having uneven portions on the surface of the pulp fiber layer. .. By combining the methods, a more prominent uneven portion can be formed in the pulp fiber layer.

Although the description of the embodiment is completed above, it is needless to say that the present invention is not limited to the above embodiment and can be variously modified and implemented without departing from the gist thereof.

1 Composite non-woven fabric manufacturing equipment 2 Air-laid equipment 3 Synthetic fiber web supply equipment 4 Suction equipment 5 Water flow injection equipment 6 Drying equipment 7 Winding equipment 21 Defibering machine 22 Duct 23 Air-laid hopper 24 Laminating position 28 Holding roller 30 Pre-wet equipment 31 Spraying Nozzle 32 Suction device 41 Suction device body 42 Suction part 43 Conveying wire 51 Water flow injection nozzle 52 Suction device 55 Conveying wire 510 Water flow injection nozzle 520 Opening 521 Water impermeable part 550 Conveying wire 551 Warp 551B Thick warp 552 Weft pulp 552 Fiber (pulp fiber layer)
PWeb preliminary laminate CWeb laminate (composite type non-woven fabric)
SW Synthetic Fiber Web (Synthetic Fiber Layer)
DE Concave part of pulp fiber layer PR Convex part of pulp fiber layer

Claims (3)

It is a method of producing a composite non-woven fabric in which a pulp fiber layer is laminated on a synthetic fiber layer and integrated.
A water jet is sprayed onto the preliminary laminate formed by the synthetic fiber layer and the pulp fiber placed on the synthetic fiber layer to perform a water flow entanglement treatment, and the pulp fiber layer and the synthesis are performed. Including at least a water flow entanglement step that promotes integration with the fiber layer,
In the water flow entanglement step, the preliminary laminate is placed on a transfer wire and conveyed, and the water jet is sprayed toward the pulp fiber layer from a plurality of water flow injection nozzles arranged in a direction perpendicular to the transfer direction. In a device in which suction is performed by a suction device arranged under the transport wire and a plurality of streaky uneven portions are formed on the surface of the pulp fiber layer with a position corresponding to the water flow injection nozzle as a recess.
The plurality of water flow injection nozzles have a nozzle diameter of 0.15 to 0.25 mm, and the plurality of water flow injection nozzles are arranged in a plurality of stages along the transport direction.
Before and after the second water flow confounding treatment by the multi-stage water flow injection nozzle, a water jet is blown toward the entire surface of the pulp fiber layer using a water flow injection nozzle having a diameter smaller than that of the multi-stage water flow injection nozzle. A method for producing a composite non-woven fabric, which comprises performing a first water flow entanglement treatment . It is a method of producing a composite non-woven fabric in which a pulp fiber layer is laminated on a synthetic fiber layer and integrated.
A water jet is sprayed onto the preliminary laminate formed by the synthetic fiber layer and the pulp fiber placed on the synthetic fiber layer to perform a water flow entanglement treatment, and the pulp fiber layer and the synthesis are performed. Including at least a water flow entanglement step that promotes integration with the fiber layer,
In the water flow entanglement step, the preliminary laminate is placed on a transfer wire and conveyed, and the water jet is sprayed toward the pulp fiber layer from a plurality of water flow injection nozzles arranged in a direction perpendicular to the transfer direction. , Suction with a suction device arranged under the transfer wire,
The transport wire is formed of a plurality of warp threads and weft threads, and has a form in which a plurality of thick threads having a diameter larger than that of the other threads are arranged at intervals for at least one of the warp threads and the weft threads. A composite type characterized in that a plurality of streaky uneven portions or a plurality of vertical and horizontal lattice-shaped uneven portions are formed by forming a plurality of recesses on the surface of the pulp fiber layer corresponding to the position of the thick yarn. Non-woven fabric manufacturing method . A manufacturing method for manufacturing the composite non-woven fabric by combining the manufacturing methods according to claim 1 and 2 .

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